pow(-1,0) = 1, -1**0 = -1, why?
Gary Herron
gherron at aw.sgi.com
Tue Dec 19 14:17:08 EST 2000
Kirby Urner wrote:
>
> Python 2.0 (#8, Oct 16 2000, 17:27:58) [MSC 32 bit (Intel)] on win32
> Type "copyright", "credits" or "license" for more information.
> IDLE 0.6 -- press F1 for help
>
> >>> -1**0
> -1
> >>> pow(-1,0)
> 1
> >>> -10**0
> -1
> >>> pow(-10,0)
> 1
>
You're getting confused by operator precedence here.
The expression
-1**0
is interpreted as
-(1**0)
evaluates, with no surprises, to
-1.
On the other hand,
(-1)**0
evaluates to
1,
as does pow(-1,0).
--
Dr. Gary Herron <gherron at aw.sgi.com>
206-287-5616
Alias | Wavefront
1218 3rd Ave, Suite 800, Seattle WA 98101
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